Cement asphalt ballast grout composition for track

ABSTRACT

A cement asphalt ballast grout composition comprising cement, an asphalt emulsion, calcium sulfoaluminate hydrate-forming mineral, an electrolyte, a thickener and a foaming agent is excellent in the workability of mortar and in the property of hardened mortar, and is suitable as a cement asphalt ballast grout composition for directly joining-type track.

United States Patent U 115 EX Torii. et al.

1 1 Feb. 18, 1975 CEMENT ASPHALT BALLAST GROUT COMPOSITION FOR TRACKInventors: Okihiko Torii, Tokyo; Tsutomu Mizunuma, Ohmi; lwao Mino,Kamakura; Tetsuya Ando, Tokyo,

all of Japan Assignees: Japanese National Railways; Donki Kagaku KogyoKabushiki Kaisha, both of Tokyo, Japan Filed: Sept. 26, 1973 Appl. No.:400,992

Foreign Application Priority Data Sept. 26. 1972 Japan 47-95790 US. Cl106/96, 106/87. 106/97 Int. Cl C04!) 7/02 Field of Search .1 106/89. 96.87

Primary Examiner-J. Poer Attorney, Agent. or Firm-Sughrue. Rothwell.Mion. Zinn & Macpeak 57 ABSTRACT A cement asphalt ballast groutcomposition comprising cement, an asphalt emulsion. calcium sulfoaluminate hydrate-forming mineral. an electrolyte. a thickener and a foamingagent is excellent in the workability of mortar and in the property ofhardened mortar.

and is suitable as a cement asphalt ballast grout composition fordirectly joining-type track.

6 Claims, 7 Drawing Figures PATENIEU FEB 1 8 I973 SHEEI 1 [1F 5 3' Q R5/20 I, T I20 5 I o Q S I00 E. 80- I, 6 g 00 s 60 i Comparative test S40- 50 2 Example s A A M A O k /8 l8 l9 /9 20 20 0 l l 1 l l Mixing time(min) PATENTED 81975 3. 867". 161

SHEET 2 OF 5 I Q 4 Maria! famp..5 C

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g 0 I fla r araf/vo In! a E Q 2 34 6 I2 24 ,3 8 Wm: (hr) F/GLJb 2? V 4 FMortar :omp-IZO'C- Q; E Example I 2% 2- =2 $3 I u Comparafiva fast a g s2 g l 23 4 6 I2 24 Sinking CEMENT ASPHALT BALLAST GROUT COMPOSITION FORTRACK The present invention relates to a cement asphalt ballast groutfor track.

In the conventional track, correction of irregularity of track andrenewal of ballast are often necessary, and a great deal of labor isrequired in the maintenance of the track. In order to obviate suchdrawbacks, various maintenance-free track structures have beendeveloped. Among these track structures, the slab track, which isproduced by injecting cement asphalt mortar (hereinafter referred to asmortar) under the concrete slab, is a most preferable track. Because, inthe slab track the irregularity of track hardly occurs, and the sinkingof track can be restored by injecting mortar, and therefore themaintenance of the slab track is very easy.

A method for constructing the slab track will be explained withreference to FIG. 1. A roadbed concrete 1 is firstly placed, a concreteslab 2 is arranged on the roadbed concrete I, adjusted by a jack so asto form a planned alignment and then supported at four points bysupporting rods, a space 3 formed between the roadbed concrete 1 and theconcrete slab 2 is enclosed with a frame, a mortar is injected into thespace 3 through holes 5, and after the mortar reached a predeterminedstrength, rails 4 are laid.

The mortar to be injected in the above described method is required tosatisfy the following conditions.

1. The physical properties of the mortar satisfies the dynamic theoryfor track.

2 The mortar has workability.

That is, mortars having the following physical properties areadvantageously used in the construction of the slab track.

1. The mortar has a compressive strength of 10 2O Kg/cm? 2. The mortarhas an elasticity of 0.5 5.0 10

Kg/cm 3. The mortar, at the injection, has such a consistency that theflow down time through the J-funnel is 17 26 seconds.

4. After injection, the mortar does not separate.

5. The hardened mortar does not cause dry shrinkage.

6. The fineness modulus of sand'in the mortar is not limited.

In the conventional cement asphalt grout, a mixture of an anionic,cationic or nonionic asphalt emulsion with cement has been used.However, when this cement asphalt grout is used in the above describedmethod, the resulting mortar has sufficient compressive strength andelasticity, but is still insufficient in the other various physicalproperties.

The present invention provides a cement asphalt ballast groutcomposition for directly joining-type track, which comprises 100 partsby weight of cement, 20 400 parts by weight of an asphalt emulsion, 20parts by weight of a calcium sulfoaluminate hydrate-forming mineral, 0.15.0 parts by weight of an electrolyte, 0.01 5.0 parts by weight of athickener and 0.01 0.03 part by weight of a foaming agent.

The cement to be used in the present invention includes Portland seriescement, mixed cement and the like.

As the calcium sulfoaluminate hydrate-forming mineral to be used in thepresent invention, mention may be made of, for example, type K, type Mand type S minerals described in American Concrete Institute Journal,1970, No. 8, pages 584 589. Among these minerals, ones having a finenessof a Blaine value of 4,000 10,000 cm /g are preferably used.

The calcium sulfoaluminate hydrate-forming mineral is used in an amountof 5 20 percent by weight based on the weight of cement. Among the abovedescribed calcium sulfoaluminate-forming minerals, ones having such aproperty that a cement mortar prepared from 5 20 percent by weight ofthe mineral and the remainder of cement has a free expansion coefficientof about 0.05 0.5 percent are preferably used.

Furthermore, when a mixture of percent by weight ofa powdery calciumsulfoaluminate series mineral and 15 5 percent by weight of a powderymineral consisting mainly of 3CaO-3Al O -CaF is usedin an amount of5 20percent by weight based on the weight of cement, a cement asphalthardened mortar having a higher strength can be obtained.

The calcium sulfoaluminate hydrate-forming mineral forms calciumsulfoaluminate hydrate, that is, ettringite, in the resulting mortar andthe mortar expands for about 7 days. Therefore. the sinking of themortar, just after the placing, can'be prevented by the actions ofthefoaming agent and the ettringite, and further the shrinkage of thehardened mortar due to drying does not occur and cracks does not appearin the hardened mortar.

The mortar of the present invention shows the thixotropy phenomenon bythe actions of the powdery cal cium sulfoaluminate hydrate-formingmineral and the thickener. That is, the mortar has a good fluidityduring the mixing and injection operations, and in the static I stateafter the mortar is injected, the viscosity of the mortar increasesquickly, and the separation of sand can be prevented.

The thickener to be used in the present invention includes polyvinylalcohol, carboxymethylcellulose, starch, gelatine, etc., and mixturesthereof. The thickener is used in an amount of 0.01 5.0 percent byweight based on the weight of cement.

The electrolyte to be used in the present invention includes sodiumchloride, lithium chloride, potassium chloride, calcium chloride,magnesium chloride, barium chloride, etc., and mixtures thereof. Theelectrolyte is used in an amount of 0.1 5.0 percent by weight based onthe weight of cement. The electrolyte prevents the decomposition ofasphalt emulsion, and can prolong the time of gelation of mortar.

The foaming agent to be used in the present invention includes aluminum,aluminum nitride, zinc, tin, calcium silicon alloy, etc., and mixturesthereof. The

foaming agent is used in an amount of 0.01 0.03 per-- cent by weightbased on the weight of cement.

Theasphalt emulsion is used in an amount of 20 400 percent, preferably300 percent by weight, based on the weight of cement. When the additionamount is less than 20 percent by weight. the elasticity of the hardenedmortar is too high, and the characteristic property of the cementasphalt is lost. While, the addition amount exceeds 400 percent byweight, a very long time is required in the hardening of mortar.

It is desirable that the asphalt emulsion to be used in the presentinvention is stable against alkaline subacid salt, sulfuric acid esterof higher alcohol, sulfate of 5 aliphatic amine or aliphatic amide,phosphoric acid ester of aliphatic alcohol, and the like, and onescontaining nonionic surfactants, such as polyoxyethylene alkyl ether,polyoxyethylene alkylpheno] ether, sorbitan aliphatic acid ester and thelike, can be used in the present invention.

As described above, the mortar produced from the grout composition ofthe present invention is small in the variation of consistency, has alow sinking percentage even when the temperature is varied, and furtherdoes not cause separation of raw materials during the hardening, and thehardened mortar does not cause dry shrinkage. Accordingly, the groutcomposition of the present invention is an excellent cement asphaltballast grout composition for directly joining-type track.

For a better understanding of the invention, reference is taken to theaccompanying drawings, wherein:

FIG. 1 is a perspective view of a slab track;

FIG. 2 is a graph showing the consistency of mortar;

FIG. 3 is a graph showing the sinking percentage of mortar;

FIG. 4 is a graph showing the separation of raw mate rials in thehardened mortar; and

FIG. 5 is a graph showing the shrinkage of the hardened mortar due todrying.

In each of FIGS: 2 5, the mortar of the present invention and that ofcomparative test produced in the following Example 1 are compared inorder to explain the merit of the present invention.

The following examples are given for the purpose of illustration of thisinvention and are not intended as limitations thereof.

EXAMPLE 1 A mixture of 160 parts by weight ofa cationic asphaltemulsion, l5 parts by weight of a powdery mineral (Blaine value: 6,000cm /g) consisting mainly of 3CaO" 3Al O -CaSO,, 0.45 part by weight oflithium chloride, 0.1 part by weight of a blend of polyvinyl alcohol andcarboxymethylcellulose in a ratio of 50:50 (by weight), 0.013 part byweight of powdery aluminum, 85 parts by weight of Portland cement, 200parts by weight of sand and parts by weight of water'was mixed in avertical type mixer.

ing at 1,350C a powdery mixture of 19 parts by weight of CaO (purity: 96percent), 35 parts by weight of Bauxite (purity: 86 percent) and 46parts by weight of anhydrous gypsum.

For a comparison, a mixture of 100 parts by weight of Portland cement,200 parts by weight of a cationic asphalt emulsion, 200 parts by weightof sand, 1.5 parts by weight of powdery aluminum and 25 parts by weightof water was mixed in the same manner as described above.

The above obtained mortar of the present invention and that of thecomparative test were tested with respect to the flow time(consistency), sinking percentage, separation of raw materials, dryshrinkage, compressive strength (age: 28th day) and elasticity (age:28th day).

The flow time test was effected by changing the mixing time as shown inthe following Table l. The sinking percentage was measured by using amortar which was prepared by mixing the raw material mixture for 20minutes. The tests for the separation of raw materials, the dryshrinkage, the compressive strength and the elasticity were effected byusing a hardened mortar. which was prepared from the same mortar as usedin the test for sinking percentage.

The test method are as follows.

1. Flow time (consistency):

The flow down time (unit: second) of a sample mortar through a J-funnelhaving a capacity of 700 ml and provided with a leg of 1 cm diameter ismeasured.

2. Sinking percentage:

The sinking percentage is measured by a cylinder method at a mortartemperature of 5, 20 or 35C. 3. Separation of raw materials:

Samples are taken from the hardened mortar having a thickness of 50 mmat 10 mm intervals from the upper surface of the mortar. Each of thesamples is extracted by means of a Soxhlets extractor, and thedistribution of asphalt in the hardened mortar is measured.

4. Dry shrinkage:

The dry shrinkage is measured by a comparator method.

5. Compressive strength:

The compressive strength is measured by means of a one axis compressiontester. 6. Elasticity:

The elasticity is measured by means of an automatic elasticity measuringapparatus.

The above described powdery mineral cons sting 5 The obtained resultsare shown in the following Table mainly of 3CaO-3Al O -CaSO was producedby burn- 1 and in FIGS. 2 5.

Table 1 Example 1 Comparative test Mixing time (min.) Mixing time (min.)

Flow down time 5 l0 15 2O 25 3O 5 IO 15 20 25 30 through the .l-funnel(see) l8 l8 l9 19 20 20 I8 50 I00 5C 20C 35C 5C 20C 35C Influence ofexpand expand expand sunk by sunk by expand temperature upon after afterafter 1% after 0.5% by 3; sinking percentage 6 hours 1 hour 30 min. 1hour after after 1 hour 3 hours Table l Continued Example 1 Comparativetest Mixing time (min.)

Mixing time (min) Separation of ll Kg/cm '1 Asphalt is present in thehardened mortar from the upper surface thereof to a distance of 15 mm ina larger amount than the IhQtItCIILZll amount. '2 At an age 0128 days.the shrinkage of the upper surface of the hardened mortar is l.51.undthe shrinkage of the lower surface of the hardened mortar is tlj'l.

The results obtained in the above described tests will be explained moreminutely with reference to FIGS. 2 l5 FIG. 2 shows a relation betweenthe mixing time of a mortar and the flow down time (unit: second) of themortar through the J-funnel.

It is clear from FIG. 2 that the mortar of the present invention has aconstant flow down time through the J-funnel within the range of 18 20seconds.

FIG. 3 shows sinking percentages of a mortar kept at mina (purity: 99.5percent), 11.9 parts by weight of calcium fluoride (purity: 95 percent).and 43.8 parts by weight of calcium carbonate (purity: 99 percent) wasmelted at a temperature of 1,400C and cooled, and the resulting melt waspulverized to a Blaine value of 6,000 cm /g. It was confirmed from theX-ray diffractiometry that this product was 3CaO-3Al O 'CaF mineral.

The above described calcium sulfoaluminate series mineral had a chemicalcomposition as shown in the following Table 2.

Table 2 Ignition Insoluble Total CaO loss component SiO A1 F6203 (FreeCaO) MgO 50 Total temperatures of and C. It can be seen from FIG. 3 thatthe mortar of the present invention does not substantially sink evenwhen the temperature is varied.

FIG. 4 shows a relation between the distance from the upper surface ofahardened mortar and the amount of asphalt contained in the hardenedmortar at the distance. In FIG. 4, the ordinate represents theunevenness of the amount of asphalt from the theoretical amount in thehardened mortar, and the mark means that the amount of asphalt issmaller than the theoretical amount and the mark means that the amountof asphalt is larger than the theoretical amount.

It is clear from FIG. 4 that asphalt is distributed uniformly in thehardened mortar of the present invention.

FIG. 5 shows a relation between the age (day) of a hardened mortar andthe shrinkage of the hardened mortar due to drying. It is clear fromFIG. 5 that the hardened mortar of the present invention does not shrinkat all.

EXAMPLE 2 A mortar was prepared and tested under the same condition asdescribed in Example 1, except that a powdery mixture of 13.5 parts byweight of a calcium sulfoaluminate series mineral and 1.5 partsby weighta mineral consisting mainly of 3CaO3Al O CaF was used as a calciumsulfoaluminate hydrate-forming mineral, and 0.45 part by weight ofsodium chloride was used instead of lithium chloride.

The obtained results were the same as the results obtained in Example 1,except that the hardened mortar at the age of 28 days had a compressivestrength of 15 Kg/cm and an elasticity of 1.8X1O Kg/cm The abovedescribed mineral consisting mainly of 65 3CaO-3Al O -CaF was producedin the following manner. A powdery mixture of 44.3 parts by weight ofalu- What is claimed is:

l. A cement asphalt ballast grout composition for directly joining-typetrack, which comprises 100 parts by weight of cement, 20 400 parts byweight of an asphalt emulsion, 5 20 parts by weight of a calciumsulfoaluminate hydrate-forming mineral, 0.1 5.0 parts by weight of anelectrolyte, 0.01 5.0 parts by weight of a thickener and 0.01 0.03 partby weight of a foaming agent.

2. The grout composition as claimed in claim 1, wherein said calciumsulfoaluminate hydrate-forming mineral is a mixture of percent by weightof a powdery calcium sulfoaluminate series mineral and 15 5 percent byweight of a powdery mineral consisting mainly of 3CaO'3Al O 'CaF 3. Thegrout composition as claimed in claim I,

wherein said calcium sulfoaluminate hydrate-forming mineral has such aproperty that a cement mortar prepared from the mineral and cement has afree expansion coefficient of 0.5 0.5.

4. The grout composition as claimed in claim 1, wherein said electrolyteis at least one compound selected from the group consisting of sodiumchloride, potassium chloride, lithium chloride, calcium chloride,magnesium chloride and barium chloride.

5. The grout composition as claimed in claim 1,

wherein said thickener is at least one compound selected from the groupconsisting of polyvinyl alcohol, carboxymethylcellulose, starch andgelatine.

6. The grout composition as claimed in claim 1, wherein said foamingagent is at least one compound selected from the group consisting ofaluminum, aluminum nitride, zinc, tin and calcium silicon alloy.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 13,867,161 DATED February 18, 1975 INVENTOR(S) Okihiko TORII et 2.1

It is certified that error appears in the above-Identified patent andthat said Letters Patent are hereby corrected as shown below:

IN THE HEADING:

Under Assignees: Correct second Assignee's name to read Denki KagakuKogyo Kabushiki Kaisha Signed and sealed this 27th day of May 1975.

(SEAL) Attest:

' C. MARSHALL DANN RUTH C. MASON Commissioner of Patents AttestingOfficer and Trademarks

1. A CEMENT ASPHALT BALLAST GROUT COMPOSITION FOR DIRECTLY JOINING-TYPETRACK, WHICH COMPRISES 100 PARTS BY WEIGHT OF CEMENT, 20-400 PARTS BYWEIGHT OF AN ASPHALT EMULSION, 520 PARTS BY WEIGHT OF A CALCIUMSULFOALUMINATE HYDRATEFORMING MINERAL, 0.1-5.0 PARTS BY WEIGHT OF ATHICKENER AND 0.01 0.01-5.0 PARTS BY WEIGHT OF A THICKENER AND 0.01-0.03PART BY WEIGHT OF A FOAMING AGENT.
 2. The grout composition as claimedin claim 1, wherein said calcium sulfoaluminate hydrate-forming mineralis a mixture of 85 - 95 percent by weight of a powdery calciumsulfoaluminate series mineral and 15 - 5 percent by weight of a powderymineral consisting mainly of 3CaO.3Al2O3.CaF2.
 3. The grout compositionas claimed in claim 1, wherein said calcium sulfoaluminatehydrate-forming mineral has such a property that a cement mortarprepared from the mineral and cement has a free expansion coefficient of0.5 - 0.5.
 4. The grout composition as claimed in claim 1, wherein saidelectrolyte is at least one compound selected from the group consistingof sodium chloride, potassium chloride, lithium chloride, calciumchloride, magnesium chloride and barium chloride.
 5. The groutcomposition as claimed in claim 1, wherein said thickener is at leastone compound selected from the group consisting of polyvinyl alcohol,carboxymethylcellulose, starch and gelatine.
 6. The grout composition asclaimed in claim 1, wherein said foaming agent is at least one compoundselected from the group consisting of aluminum, aluminum nitride, zinc,tin and calcium silicon alloy.